1. Technical Field
The invention relates to a fuel supply device for an internal combustion engine, comprising a constant level chamber formed in a casing placed in the vicinity of the engine.
The invention is particularly suitable for use in carburetors whose constant level chamber is generally formed in the body of the carburetor itself, consisting of a casting. The constant level chamber of such a carburetor receives heat from the engine when the latter is hot. When the engine is stopped, the carburetor is not cooled any more by air expansion and fuel evaporation within it through the carburetor. The fuel contained in the chamber can be heated to boiling point and overflow, at least partially, into the induction passage. An attempt to restart the engine may fail due to an excessive fuel/air ratio of the mixture delivered to the engine.
2. Prior Art
This problem has been known for long. Attempts have been made to solve it in different ways, particularly by placing an insulating plate between the intake pipe of the engine and the carburetor. But such insulation is often insufficient, for the metal bolts fixing the body of the carburetor to the duct form a heat leak path. Attempts have also been made to cool the carburetor body by a flow of fuel from the tank (German No. 84 06706, French No. 2,036,327, U.S. Pat. No. 3,196,926 to Gartland). This solution complicates a circuit transporting very inflammable liquid.